The objective of this study is to evaluate the hypothesis that, in patients with attention deficit hyperactivity disorder (ADHD), behavior is modulated by the glycemic index (GI) of ingested foods. Symptoms of inattention and hyperactivity will improve when lower GI foods are ingested, and worsen when higher GI foods are taken. Background: The effects of diet on children's behavior in general, and the effects on children with ADHD in particular have been studied extensively. although multiple investigation into the effects of sucrose, food additives, and possible multiple food allergies have been performed, no consistent pattern of effect has been shown. The GI was first developed in the early 1980's as a more precise way of categorizing carbohydrate exchanges in the control of diabetes. As the GI was further developed and standardized, the impact not only of food content was emphasized, but also form, particle size, processing, and the nature of starch contained in the food. Recent research has demonstrated other physiologic effects after ingestng high GI foods. In additon to the direct glycemic effects, rapid and significant initial rises and subsequent falls in blood glucose levels to below baseline were seen, along with an accompanying rise in blood levels of growth horone and epinephrine. Immediate behavioral effects included an increase in appetite and food intake. Anectdotal evidence from the parents indicate that the low GI diet has had additional effects on their children's behavior. Most notably, parents reported that their children wer better able to pay attention, have done better in school and are in trouble less often. The relationship between GI and childhood behavior problems such ADHD has not been studied. The GI may provide the link betweeen diet and behavior that parents report, but has not been properly controlled for in previous studies.